Abstract：
Porous poly (lactic-co-glycolic acid)/β-tricalcium phosphate/Icaritin (PLGA/β-TCP/ICT, PTI) scaffold is a tissue engineering scaffold based on PLGA/β-TCP (PT) containing Icaritin, the main active ingredient of the Chinese medicine Epimedium. Due to its excellent mechanical properties and osteogenic effect, PTI scaffold has the potential to promote bone defect repair. However, the release of ICT from the scaffolds is difficult to control. In this study, we constructed Ti3C2Tx@PLGA/ICT microspheres (TIM) and evaluated their characterization as well as ICT release under near-infrared (NIR) irradiation. We utilized TIM to modify the PT scaffold and performed biological experiments. First, we cultured rat bone marrow mesenchymal stem cells on the scaffold to assess biocompatibility and osteogenic potential under on-demand NIR irradiation. Subsequently, to evaluate the osteogenic properties of TIM-modified scaffoldin vivo, the scaffold was implanted into a femoral condyle defect model. TIM have excellent drug-loading capacity and encapsulation efficiency for ICT, and the incorporation of Ti3C2Txendows TIM with photothermal conversion capability. Under 0.90 W cm-2NIR irradiation, the temperature of TIM maintained at 42.0 ± 0.5 °C and the release of ICT was accelerated. Furthermore, while retaining its original properties, the TIM-modified scaffold was biocompatible and could promote cell proliferation, osteogenic differentiation, and biomineralizationin vitro, as well as the osteogenesis and osseointegrationin vivo, and its effect was further enhanced through the modulation of ICT release under NIR irradiation. In summary, TIM-modified scaffold has the potential to be applied in bone defects repairing.
摘要：
多孔聚乳酸-羟基乙酸共聚物/β-磷酸三钙/淫羊藿苷(PLGA/β-TCP/ICT,PTI)支架是一种基于PLGA/β-TCP的组织工程支架，中药淫羊藿的主要活性成分。由于其优异的机械性能和成骨效果，PTI支架具有促进骨缺损修复的潜力。然而,ICT从脚手架中的释放很难控制。在这项研究中,我们构建了Ti3C2Tx@PLGA/ICT微球（TIM），并评估了其表征以及在近红外（NIR）辐射下的ICT释放。我们利用TIM修饰PT支架并进行生物学实验。首先,我们在支架上培养了大鼠骨髓间充质干细胞，以评估在按需NIR照射下的生物相容性和成骨潜能。随后，评价TIM改性支架的体内成骨性能,将支架植入股骨髁缺损模型。TIM具有优异的药物负载能力和ICT封装效率，Ti3C2Tx的掺入赋予了TIM光热转化能力。在0.90Wcm-2近红外辐射下，TIM的温度保持在42.0±0.5°C，ICT的释放加速。此外，在保留其原始属性的同时，TIM修饰的支架具有生物相容性，可以促进细胞增殖，成骨分化，和体外生物矿化，以及体内的成骨和骨整合，通过调节NIR辐射下ICT的释放，其效果进一步增强。总之,TIM修饰的支架具有应用于骨缺损修复的潜力。
